1. Field of the Invention
The present invention is directed to a fuel cell structure in which an anode electrode and a cathode electrode are disposed in facing relation to each other with an electrolyte membrane interposed therebetween, and wherein a separator is provided for supporting the fuel cell structure interposed therebetween.
2. Description of the Related Art
There have been developed fuel cells comprising, for example, a plurality of stacked fuel cell units each having an anode and a cathode provided in opposing relation with an electrolyte membrane sandwiched therebetween, the fuel cell units further being interposed between separators. Such fuel cells are being put to practical use in a variety of applications.
Such types of fuel cells, for example, are structured such that a hydrogen gas (i.e. a fuel gas) which is generated by a methanol vapor reforming is supplied to a anode electrode, and an oxygen-containing gas (air) is supplied to a cathode electrode, whereby the hydrogen gas becomes ionized and flows through a solid polymer electrolyte membrane, thereby generating electrical energy out of the fuel cell.
In this case, in order that efficient generation of electrical power from the fuel cell can be exhibited, it is necessary to cool the anode and cathode electrodes of the fuel cell. For this purpose, for example, a structure wherein conduits for cooling water are provided in the separators, and wherein cooling water is supplied through said conduits, has been widely employed.
However, with the fuel cell having the structure described above, a problem has arisen in that when the fuel cell is used in especially cold regions, the cooling water in the fuel cell can become frozen. As a result, prior to initiating operation of the fuel cell, it becomes necessary to undertake an operation for melting the frozen cooling water, and such an operation is both troublesome and time consuming.